During taking off and landing of an airplane, since the trailing edge of the flap usually subjected to the collision of objects from the ground, the probability that the trailing edge of the flap is damaged is higher. In this case, the trailing edges of the flaps of all of the large airplanes are designed in a separable form, and then the trailing edge of the flap 1 is connected with the main member 2 of the flap by rivets 3, as shown in FIG. 1, so as to be replaced by itself when repairing, wherein the trailing edge of the flap is, for example, an aux-spar which is made of three pieces of sheet metal, which are bonded or welded together.
In the connection region of the main member of the flap and the trailing edge of the flap, there are about several hundreds of rivets along the spanwise direction. When the trailing edge needs to be replaced during a repairing process, all the rivets will be removed and reinstalled, and a new trailing edge is connected to the main member using larger type of rivets. There are following disadvantages in the prior art: a. over many rivets make repairing process is a heavy workload and will take too much time; b. the risk that the main member of the flap is damaged is increased; c. it is necessary to operate by experienced technical workers; d. the weight of the airplane is increased per repair.